OpenFOAM validation for indoor ventilation applications

Resumo

The use of Computational Fluid Dynamics (CFD) to study ventilation strategies in indoor spaces is an crucial tool for energy consumption reduction and sustainability. In this study, the application of several turbulence models for indoor ventilation modelling were validated using the OpenFOAM software. These validations were based on two experimental benchmark cases available in the literature. In the first case, an isothermal quasi 2-dimensional flow in a room with one inlet and one outlet was studied. Comparisons of URaNS simulations using the pimpleFoam solver together with the high-Reynolds number k − ε, RNG k − ε and the low-Reynolds
number LaunderSharma k − ε and k − ωSST turbulence models are presented. The second benchmark case is a three-dimensional non-isothermal flow in a room with one inlet (cold jet) and four outlets placed in a vertical opposite wall, where a heat flux is applied. The flow has an Archimedes number of 0.016. For the second case URaNS simulations were performed using the buoyantPimpleFoam solver with k − ε turbulence model with buoyant production term, and the isothermal k − ε and RNG k − ε turbulence models. In the first benchmark case all turbulence models produced a good description of the experimental flow with exception of k − ωSST that
overestimated the size of the recirculating zone and was then discarded from further tests. The second benchmark case, performed only with high-Reynolds number turbulence models, showed an overall good agreement with the experimental results, and, as almost expected, the buoyant k − ε model had the best performance pointing the importance of the buoyant term inclusion on other popular turbulence models of the OpenFOAM library.